Abstract:
Vernonia Amygdalina (VA) is a tropical African plant of the Asteraceae family and is
occasionally cultivated for its medicinal uses, which include as a treatment for diarrhea, skin
wounds, fever mastitis, body allergy and worms infection. The present study was intended to
analyse phytochemicals as well as to evaluate antimicrobial activities of stem bark extracts of
Vernonia amygdalina. The powdered stem barks of the plant were successively extracted with
petroleum ether, chloroform/methanol (1:1) and methanol respectively. The methanol,
chloroform/methanol (1:1) and petroleum ether extracts were subjected to phytochemical
screening and the results of the screening revealed the presence of a diverse phytochemicals
in reference to the solvents. The stem bark oil was extracted with n-hexane by using Soxhlet
apparatus and its chemical compositions were characterized by GC-MS. The GC-MS analysis
of n-hexane extract led to the identification of 25 compounds from Vernonia amygdalina
representing 100.01% of the extracted oil. Among them, 9,12-octadecanoic acid, methyl ester
(29.47%), hexadecanoicacid, methyl ester (14.75%), 9,12,15-octadecatrieneoic acid, Methyl
ester, (Z, Z, Z) (8.77%), 1H-indole (6.53%) were the prevailing compounds. Antimicrobial
activities of crude extracts, pure compound, and stem barks oil were performed against four
bacterial and two fungal species. All the tested samples were active against all bacterial
species at a dose of 20µg/mL. The crude extracts were also subjected to test their
antitubercular activity and the results showed that the MeOH extract was very active at
minimum concentration (3.12 MIC (µg/mL)) against M. tuberculosis. Therefore, the biological
activities displayed by the extracts and isolated compounds from this plant corroborate the
traditional uses of this plant by the local people against various diseases.
